Jerome knows he has a lot on his plate: 16 teams, 300 kids, and—between coaching, raising money, running the academic programs, and being a boss—a seven-day-a-week work schedule. It's hard to talk to him without his e-mail pinging, his phone buzzing, or someone interrupting. He grew up in Manhattan, born to a white father and a black mother who were active in civil rights causes. He was a high-school star and played some college ball. Four years ago, he was selected to take over the Riverside program, which was in danger of closing for good.

Since then, Jerome's teams—which play aggressive, pressing defense and a flowing, passing offense—have won three AAU national championships. Last summer, a team coached by Tony Hargraves, who was one of the state's top scorers in high school, finished ninth in the 14-and-under division out of 150 teams. Riverside teams have won or placed high in countless local and regional tournaments during that period.

"When it's done right, kids get a chance to play good competition in a positive environment—they learn teamwork, self-esteem, and there's academic training as well," the coach says.

Sam Horine

The Riverside Hawks do their thing in a March game.

Sam Horine

I first met him about three years ago, when I brought my son to try out for the Hawks' fourth-grade team. About five minutes into the tryout, my son threw a pass without much intensity, and Jerome made him pay for it by telling him to do five push-ups. I will never forget how my son looked up at me, his eyes as big as saucers. He had never done a push-up as punishment before.

"The main thing that distinguishes this is that it is competitive ball, as opposed to recreational ball, and winning is an important goal, among many other goals," says Rob Stevens, another father whose son plays for Jerome. "I've seen coaches push kids way over the line, but Mark has an intrinsic sense about pushing as hard as he can without crossing the line, while empathizing with the kids and teaching skills and teamwork. I haven't seen a coach better than Mark."

As practice begins, Jerome confesses to a lingering ache over a loss the previous Sunday in a Queens tourney. His team had been up by six with two minutes to go. Losing bothers him, and he is thinking about the loss far more than he is about the team's championship that same weekend in a different tournament sponsored by NBA player Ron Artest.

He switches the boys from the three-man weave to a continuous series of three-on-three scrimmage. He yells at a kid who is only going at half-speed.

Compared to the years of Riverside's dominance, the big change that exists in elite youth basketball now is that there are many more teams and everyone is playing a lot more, he says. There's a higher skill level at all ages. Even wealthy Manhattanites bring their kids to Riverside to improve their basketball skills.

"Some of the parents don't understand the commitment that it takes to excel at this level," he says. "If you're not playing year-round, you can't keep up. And people don't realize how good you have to be to play at a high level."

Only a select group can really thrive in the world, he says. "I used to think anybody could do it, but I now believe only about 10 percent of kids have the physical ability and the emotional strength to withstand the pressure of playing in some of these intense environments," he says. "I get calls all the time from parents who say their kids are really good—and then they come here, and their jaws drop. You worry that the kid will never pick up a ball again."

He adds that he wants greater loyalty from the parents, and he wishes that, as a class, they would relax. "I wish they would calm down, be patient, and see the big picture," he says. "It's not so much where their kid is right now, but where he will be down the road. . . . You have crazy coaches, and you also have parents who get impatient, who move their kids from team to team. I think that sends the wrong message."

He sees some sloppy play on the court and orders the boys to play Taps—the old game in which a kid throws the ball off the backboard to the next kid, who catches it in mid-air and repeats the move. Only, his version involves a full-court sprint and 100 repetitions. The ball cannot touch the ground. The drill runs for 20 minutes. By the time they get a water break, the boys are exhausted.

Sometimes, Jerome runs a layup drill, in which the kids have to sprint from half-court and make 20 left-handed layups in a row. With each miss, they have to do five push-ups and start over. He believes that this teaches them concentration.

It's a hothouse environment, and no matter where you start, you will improve if you stick with it, Jerome believes. He points to a towering, gawky kid from Harlem who came in never having played basketball. "You look at him," Jerome says. "He's made great strides already."